Fetal kidney length as a parameter for gestational age determination and its comparative evaluation with other fetal biometric indices

Background: An accurate estimation of foetal gestation age is of utmost clinical significance owing to its vast clinical implications principally in management of high risk pregnancies. Aim: To determine correlation and regression coefficient of foetal kidney length as a parameter for gestational age and to do its comparative evaluation with other foetal biometric indices. Materials and methods: A Prospective observational study was conducted on 200 women aged between 18 to 35 years with normal singleton pregnancies, over a duration of six months from December 2015 to May 2016. Gestational age and fetal kidney length was determined using Ultrasound machine PHILIPS HD7 (2.0.1) with 3- 5 MHz curvilinear transducer. Statistical analysis was done using tests of correlation and simple linear regression. All analysis was done by using IBM SSPS statistics 24and MS excel. Results: Pearson's correlation coefficient value of 0.99 and regression coefficient or slope 1.0 noted between gestational age and fetal kidney length with a significance P< 0.001. Conclusions: Fetal kidney length shows a positive correlation with fetal gestational age, with a linear growth rate throughout pregnancy irrespective of underlying medical condition like intrauterine growth retardation. This study shall prove its worth in cases of engaged fetal head, where it is difficult to measure fetal bi parietal diameter and head circumference as well as in cases of intrauterine growth retardation, macrosomia and malformation where abdominal circumference measurement gives false values.